X-ray systems are commonly employed for such applications as the inspection of materials or containers by illuminating the material or container from the outside by means of fan beams. A fan beam refers to a beam having an opening angle in one dimension substantially larger than the width of the beam in a dimension orthogonal to the first. Additionally, the use of a pencil beam, scanned across the object under inspection is also known and used in the art.
The concurrent or alternating application of one or more fan beams and one or more pencil beams is the subject, for example, of copending provisional application No. 60/072,890, filed Jan. 28, 1998, which is herein incorporated by reference.
The methods known in the art for concurrently applying multiple beams require multiple sources penetrating radiation.